Synopsis On 11 September 2003, at 2057 eastern daylight time, Wasaya Flight125, a Cessna208B Caravan (serial number208B0305, registrationC-FKAB) departed Pickle Lake to Summer Beaver, Ontario, on a charter flight with seven passengers and one crew member. The flight proceeded on a direct routing to destination at 3500feet above sea level under night visual flight conditions. On approaching Summer Beaver, the aircraft joined the circuit on a downwind leg for a landing on Runway17. When the aircraft did not land, personnel at Summer Beaver contacted the Pickle Lake flight dispatch to inquire about the flight. The aircraft was declared missing following an unsuccessful radio search by the Pickle Lake flight dispatch staff. Search and rescue personnel found the wreckage in a wooded area three nautical miles northwest of Summer Beaver. The aircraft had been nearly consumed by a post-crash fire. All eight people on board had been fatally injured. Ce rapport est galement disponible en franais. 1.0 Factual Information 1.1 History of the Flight Wasaya Airways is headquartered in Thunder Bay, Ontario,1 and operates four different aircraft types from a number of bases in the northwestern part of the province. Wasaya's Cessna208B Caravan aircraft are certified for Air Taxi operations under Canadian Aviation Regulation (CAR)2703 and operate from bases at Red Lake (CYRL) and Pickle Lake (CYPL). On 11 September 2003, the occurrence pilot was on reserve status. He was called in to fly the last two flights of the day because wind conditions were quite strong, and the base manager wanted a more experienced pilot for the evening flights. The pilot reported for duty at 1700 eastern daylight time,3 completed his planning for a scheduled freight trip to Muskrat Dam and departed Pickle Lake at 1805. When he returned to Pickle Lake at 2032, the aircraft was refuelled and reconfigured for a passenger charter to Summer Beaver (CJV7). Flight 125 departed Pickle Lake at 2057 with an estimated arrival time of 2136. There were seven passengers and one pilot on board. The pilot flew a direct visual flight rules (VFR) routing to Summer Beaver at 3500feet above sea level (asl) under night visual meteorological conditions (VMC). While en route to destination, the pilot exchanged radio calls with another Caravan pilot operating in the area. Ten minutes before landing at Summer Beaver, he broadcast his intentions on 126.7MHz and activated the aircraft radio control of aerodrome lighting (ARCAL) of the airfield. Witnesses on the ground saw the aircraft's lights as it joined the downwind leg of the airport traffic circuit. The runway lights extinguished 15minutes after activation, but the aircraft had not landed. Personnel at Summer Beaver called the Pickle Lake dispatch office to inform them that the flight had not arrived. The aircraft was declared missing at 2320 following an unsuccessful radio search by the Pickle Lake base staff. Search and rescue personnel found the wreckage at 0152; all eight people on board had been fatally injured. The aircraft was lying in a wooded area, three nautical miles (nm) northwest of Summer Beaver (5243'773north, 8837'152west, elevation 835feetasl). The accident occurred at approximately 2130, during the hours of darkness. The accident was non-survivable. 1.2 Injuries to Persons 1.3 Personnel Information The pilot had been employed with Wasaya Airways since March2001, initially as first officer on the Caravan and the PilatusPC-12. As of May2003, he had been flying as a captain on the Caravan. The last entry in the pilot's logbook was dated 08August2003. Flights that had been completed after that date were not recorded in his logbook. As of 08August2003, he had accumulated a total of 132hours of night flying, 36of which were flown on the Caravan (31hours dual, 5hours as captain). A study of aircraft journey logs indicated that he had flown a further six night hours between 19August and 11September and had completed more than five night take-offs and landings, as required for carrying passengers. The pilot last flew at night the evening before the accident. The pilot's total flying hours were calculated using his personal logbook, company hours data, and aircraft journey logs. The following is a summary of personnel information. 1.4 Aircraft Information There is no record that the pilot performed weight and balance calculations before the flight, as required by CAR703.37, since no form to this effect was left in Pickle Lake, as required by regulations. However, weight and balance calculations made by the investigation team, based on the information obtained about the passengers and cargo, indicated that the weight and centre of gravity were well within the aircraft limits at take-off and for the duration of the flight. The required passenger manifest was also not completed. Initially, this made it difficult to determine with certitude who was on board the aircraft at the time of the crash. Examination of the wreckage confirmed that all of the passengers had been seated behind the cockpit bulkhead in the cabin, with no one occupying the copilot seat. 1.5 Meteorological Information On the day of the accident, the area forecast for northwestern Ontario indicated a band of convective activity extending from Kenora to Hudson Bay. This was forecast to produce broken cloud layers between 3000feet and 19000feet with numerous embedded altocumulus castellanus clouds giving a visibility of four to six statute miles (sm) in rain showers and mist. Thunderstorms were predicted in the southern half of this weather area between Kenora and Pickle Lake. Moderate mechanical turbulence below 3000feet above ground level (agl) was forecast for the entire area. The Pickle Lake terminal area forecast called for light westerly winds, visibility greater than 6sm with a ceiling of 3000feet. The Pickle Lake weather at the time of departure was as follows: light westerly winds, 12sm visibility, temperature 21C, ceiling 3000feet, with towering cumulus (TCU) cloud associated. At the time of the accident, the Pickle Lake weather was reported as follows: wind westerly at 7knots, 12sm visibility in light rain showers, and ceiling 2500feet, with TCU cloud associated. Summer Beaver does not have a weather reporting station; however, pilots operating in the area around the time of the accident reported strong southwesterly winds, moderate mechanical turbulence with no windshear, and visibility greater than 10nm. There was a light rain shower observed at the aerodrome about 20minutes after the time of the accident, but no rain at the time of the accident. 1.6 Aerodrome Information Summer Beaver aerodrome is operated by the Government of Ontario. The single runway is a gravel strip 3500feet long and 100feet wide oriented 173/353Magnetic(M), and the elevation is 832feet asl. The aerodrome is equipped with threshold and runway end lights, medium intensity runway edge lights, and type KARCAL lights. It is an uncontrolled aerodrome with a published aerodrome traffic frequency (ATF) of 123.2MHz that is to be used when within 5nm of the aerodrome and below 3800feet asl. Summer Beaver aerodrome does not have fire fighting services. 1.7 Flight Recorders The aircraft was not equipped with any on-board recording devices nor were they required by regulations. The determination of the occurrence events was hampered by the lack of on-board recording equipment. 1.8 Wreckage and Impact Information 1.8.1 General Photo1. Overhead view of the accident site Examination of the wreckage revealed that the aircraft struck heavily wooded terrain in a near vertical attitude with the wings level. The site was located 3.1nm from Summer Beaver on a 295M bearing from the threshold of Runway17. The aircraft knocked down several trees that had occupied the ground where the aircraft came to rest, and there were signs of tree impact to the leading edges of both wings. The aircraft came to rest facing 200M, with the remains of the wings nearly perpendicular to the fuselage. Fire consumed some trees and most of the aircraft, with the exception of portions of the fuselage, wings, engine, and propeller. The remains of the landing gear, seats, door latches, and cargo pod were identified. No evidence of pre-impact structural failure was identified. All major components of the aircraft were located at the accident site. No discrepancies were found with the portions of the aircraft that could be examined. Only small fragments of the windshield were found within and immediately outside of the site perimeter. 1.8.2 Engine and Propeller The engine was located under the forward fuselage structure, upright and aligned approximately with the aircraft longitudinal axis. The engine displayed severe impact and fire damage, including the complete consumption of the reduction and accessory gearbox housings. Extreme fire damage precluded assessing the pre-impact continuity of any of the engine-to-airframe connections, or power controls and related gauges. There were no indications of operational dysfunction of any of the engine components examined. The engine displayed contact signatures on the internal components, characteristic of an engine developing significant power at the time of impact. The engine did not display any pre-impact anomalies or distress that would have precluded normal operation. The aircraft was equipped with a McCauley three-bladed, constant-speed, full-feathering, reversible, governor-regulated propeller. The propeller spinner, propeller hub, and blades were found embedded approximately 1.5feet below the surface of the forest floor with portions visible at the surface. The propeller was relatively intact, with the propeller spinner crushed aft against the propeller hub. The displacement of the propeller back plate and the distortion of the mounting bolts approximately 30to 40degrees indicated propeller rotation at impact. During examination, there were no indications of operational dysfunction of any of the propeller components that would have precluded normal operation. The propeller displayed contact signatures on the internal components characteristic of a propeller producing forward thrust at a low blade angle. The governor displayed severe impact and fire damage, and an assessment of its serviceability prior to impact could not be completed. The governor counterweights and oil pump were intact. 1.8.3 Flight Controls The Caravan aircraft is equipped with flight controls consisting of ailerons; inter-connected spoilers, elevators, and rudder control surfaces; and trim tabs. The control surfaces are manually operated through mechanical linkage using a control wheel for the ailerons, spoilers, and elevator, and using rudder/brake pedals for the rudder. Manually operated aileron, elevator, and rudder trim systems are provided and controlled from the cockpit by trim wheels mounted on the control pedestal. The aircraft is also equipped with an electric elevator trim system. The wing flaps are large-span, single-slot type, incorporating trailing-edge angle and leading-edge vortex generators to reduce stall speed and provide enhanced lateral stability. The flaps are driven by an electric motor and are extended or retracted by positioning the wing flap selector lever on the control pedestal to the desired flap deflection position. Flight control cable continuity for all flight controls was determined to be normal with the exception of cuts or overload failures as a result of the impact and aircraft breakup. The positions of the ailerons, elevators, spoilers, and rudder at impact could not be determined. The position of the aileron trim tab actuator was consistent with a one-degree up, trim tab deflection. The elevator trim tab actuators were found at approximately six degrees trim tab up. The autopilot system components were destroyed by the fire; the status of the system at impact could not be determined. The flaps, flaps tracks, and flap pushrods were partially consumed by the post-crash fire. The measurement of the extension of the flap actuator jackscrew was interpreted to be equivalent to a 20flaps down position. There were no pre-impact failures identified with the flap bellcranks, and the impact damage to the bellcranks was symmetric about the wings. The flap actuator support structure, the flap motors, and the transmission were destroyed by the fire. The Transport Canada Service Difficulty Record database was queried regarding the flap system. The search produced 81service difficulty reports (SDRs) submitted between1989and2003. 1.8.4 Flight Instruments The remains of the flight instruments were found, but all were burned or damaged to such an extent that no meaningful information could be recovered. Between 05March2001 and the date of the accident, nine replacements of the flight command indicator (FCI) were recorded in the technical records of the occurrence aircraft. The reasons for these replacements varied from the instrument displaying erroneous pitch and bank information while in level flight to the unit not erecting properly or toppling. 1.8.5 Maintenance Records A review of the maintenance records for the two-year period prior to the accident indicated that the aircraft had been maintained in accordance with the maintenance program approved by Transport Canada. It was noted that the maintenance requirements of the emergency locator transmitter (ELT) and battery were overdue. However, as the ELT is not part of the certification criteria for this aircraft, the certificate of airworthiness was valid and in force. In the months leading up to the accident, numerous unserviceabilities were recorded with the FCI, flap system, and autopilot system; however, the impact forces and post-crash fire precluded determining the serviceability of this instrument and these systems at impact. In the two-year maintenance history reviewed, numerous recurring defects pertaining to the KI256FCI and the autopilot were recorded. The operator indicated that they had experienced operational and reliability problems with the KI256FCI across their fleet of Caravans. On 08May2003, this entry was made in the journey log of the accident aircraft: The Capt's attitude indicator needles shake after unit is spooled up. Unit becoming unstable after 5min in flight. The FCI, King KI256attitude indicator, S/N:X23297 was replaced with KI256, S/N:X21778. Between 08May and 05July, two more FCIs were replaced. On 05July, KI256, S/N:X23297 was re-installed in the occurrence aircraft and was the unit in place the night of the accident. The pre-impact serviceability of the occurrence FCI could not be determined as the unit was found nearly completely melted. 1.9 Medical Information There was no indication that medical issues played a role in the occurrence. The pilot's aviation medical file contained no information relating to pre-existing medical conditions that would have led to incapacitation. 1.10 Fire An intense post-crash fire consumed most of the aircraft. The accident site was accessible only by helicopter. Aerodrome fire fighting services would have been unable to reach the site had they been available. 1.11 Survival Aspects Pickle Lake flight dispatch staff commenced a radio search for the aircraft after being informed by personnel in Summer Beaver that the flight had not arrived. The aircraft was officially declared missing at 2320, and a search and rescue Hercules aircraft from Winnipeg, Manitoba was tasked to respond. At 0101, the Hercules was in the search area and reported picking up a weak ELT signal. The crash site was located at 0152; a fire was still burning at the site. Rescue personnel parachuted into the location and, after searching the area, determined that the passengers and the pilot had perished in the wreckage. The ELT had separated from the aircraft during the impact sequence and was found leaning against a tree. Rescue personnel indicated that the activation light on the ELT was illuminated when they found it, but the antennae cable had detached from the ELT. This would explain why the ELT signal was not picked up by high flying aircraft nor by the search and rescue satellites. This was not a survivable accident. Impact forces were in excess of the design limits of the restraint system, and the liveable space of the cabin was compromised. 1.12Aircraft Operating Procedures and Handling Characteristics The Wasaya Airways Standard Operating Procedures for the Cessna208B describe the standard VFR circuit, as follows: The aircraft is established on the downwind leg at 130knots with the 10flap position selected. After turning to base leg, the speed is reduced to 120knots, 20of flap is selected, and the propeller is set for maximum rpm. The aircraft is positioned on final at 500feet agl at landing reference speed (VREF) plus 15knots. Full flap is selected on short final with the intent to land. The accident aircraft was last seen on a right downwind leg for Runway17. The wreckage was found in the general area of where the turn to base leg would be expected. When the aircraft is at the maximum certified weight of 8750pounds, with the most rearward centre of gravity (CofG), and configured with 10of flap, the aircraft will stall at 58knots indicated airspeed (KIAS) while straight-and-level and at 62KIAS with 30of bank. At the same weight and CofG position with 20of flap, the aircraft will stall at 53KIAS while straight-and-level and at 57KIAS with 30of bank. The Cessna208B pilot operating handbook indicates that altitude loss during a stall recovery may be as much as 300feet from a wings-level stall and even greater from a turning stall. Cessna Aircraft company certification data4 describes the 208Bas having good stall characteristics. The data from flight testing indicated that power-on stalls required typical aileron and rudder inputs, and that the 208Bhad to be forced into a spin with aggressive rudder input. With less than a 200-pound imbalance between the fuel tanks, wing drop in the stall should not occur. Cessna Caravan pilots generally describe the 208Bas very docile in a stall. 1.13 Waterfowl Migration Numerous Canada geese were observed migrating south during the time surrounding the occurrence, and during the field phase of the investigation large flocks of geese were observed and heard overflying the area well into the hours of darkness. The accident area encompasses one of the major geese migration routes; however, there was no indication of a birdstrike on any part of the wreckage. 1.14 Company Operations Wasaya Airways Air Operating Certificate (AOC) grants authority for the company to carry passengers aboard the Cessna Caravan on instrument flight rules (IFR) and night VFR flights. The AOC also grants authority to carry passengers on IFR flights without a second-in-command. Because rules for IFR flight are more stringent than those for VFR flight, this implies that the same authority would be granted to carry passengers in night VFR conditions without a second-in-command. The pilot held a valid instrument rating required for night VFR flight with passengers. Wasaya operates a Type-C dispatch system and, as such, the pilot-in-command (PIC) retains overall responsibility for flight watch. It employs and uses flight followers to assist the PIC. Specifically, they maintain arrival and departure information, flight schedules, and meteorological and notice to airmen (NOTAM) information. As required by CAR724.15, the company's Operations Manual describes the training provided to the flight followers and the responsibilities of the PIC and the flight followers with respect to flight watch. Wasaya uses a flight dispatch clearance form in lieu of a flight plan or flight itinerary. This form contains flight information regarding routing, distance, time, and fuel. Flight progress is updated by Wasaya agents in the various aerodromes or through radio rebroadcast with other aircraft. The company also uses forms for recording the aircraft weight and balance, and for the passenger manifest. The PIC is required to complete these three forms for every flight or series of flights before departure, and a copy of each form is to be left with the departure base, or faxed to the base when operating from a satellite location. The pilot of the accident aircraft did not leave copies of any of these forms at the Pickle Lake base before departing for Summer Beaver. Flight following procedures during some stages of operations can be impractical. Changes to flight plans can only be passed by radio relay with other company aircraft when operating from remote locations or after normal working hours, as aerodrome offices may be closed, and crews do not have access to passenger agents or telephones. 1.15 Spatial Disorientation Spatial disorientation occurs when a pilot loses the ability to orient himself with respect to the horizon by using instruments or other visual references. A number of illusions affecting the visual or vestibular systems can result in spatial disorientation including: Somatogravic Illusion (pitchup, pitchdownillusion): This illusion occurs when the otoliths, structures in the inner ears, interpret a horizontal acceleration or deceleration as if the head were being tilted backward or forward. If uncorrected, this illusion will cause the pilot to pitch the nose of the aircraft in the opposite direction to compensate. The Leans: This illusion occurs when a roll is introduced slowly or maintained for a period of time. The semi-circular canals, structures in the inner ears, experience the banked attitude as being straight up and down. Once returned to straight flight, the pilot senses a turn in the opposite direction and may attempt to correct by banking in the opposite direction. Coriolis Illusion: This illusion occurs when two or three of the semi-circular canals in the inner ear are subjected to accelerations in different directions (e.g. such as might occur when turning the head and bending down while the aircraft is turning). This illusion causes a strong sensation of falling or tumbling with the danger that the pilot will attempt a take-control action opposite to the false sensation. Drift Illusions: This visual illusion occurs when operating low to the ground in strong wind conditions where the effect of wind on ground speed and drift gives the pilot a strong sensation of flying faster or slower than desired and of turning in an uncoordinated manner. The danger of this illusion lies in the pilot taking action to counter the visual illusion, possibly placing the aircraft in a slow-speed range in uncoordinated flight. Such illusions have been well documented during training for private and commercial pilot licences as well as in training for instrument ratings.5 1.16 Transport Canada Audit Between 17 and 20September2003, Transport Canada Aviation Enforcement conducted an audit of Wasaya Airways operations and maintenance divisions. The only finding of note was that the company had not been documenting the requirement to complete five take-offs and landings at night before carrying passengers. The company confirmed that the pilots had carried out the landings and take-offs, but no system had been used to record them. The company has since implemented a method of tracking night take-offs and landings.